Interpretive Summary: Genetic improvement of tropical fruit trees has lagged far behind the progress achieved in temperate fruit trees. The reasons for this are many and include the lack of resources, political stability and infrastructure in many of the lesser-developed countries where these species are grown. Nevertheless, the value of these tree fruit crops in providing locally available quality nutrition is significant. The commercial potential of these crops is often limited because of logistics involving transportation and storage. The commercial value of these crops could be greatly enhanced if cultivars were developed that were adapted to commercial production, storage, and shipping. This chapter reports on the current status of the genomics of tropical fruit tree species. A review of the literature of molecular marker development and new techniques for increasing single nucleotide polymorphic markers is discussed. Specific examples of the use of genomics are given for avocado, mango, lychee and longan. These include the development of genetic recombination maps and the potential use of Marker-Assisted-Selection in these species.

Technical Abstract:
The genetic improvement of tropical fruit trees is limited when compared to progress achieved in temperate fruit trees and annual crops. Tropical fruit tree breeding programs require significant resources to develop new cultivars that are adapted to modern shipping and storage requirements. The use of molecular markers in tropical fruit tree breeding is greatly assisting in solving a number of difficult challenges for breeders such as the development of complex family structures for recombination mapping and for recurrent selection. A review of the literature on molecular markers development and new techniques for increasing single nucleotide polymorphic markers is discussed. The development of Marker-Assisted-Breeding for these tropical tree crops is also discussed.